ftrace: Synchronize the initialization of ftrace_opsgrafted

There's some internal state that ftrace_ops needs to have set, but since
it can be declared outside of the ftrace.c code, it calls
ftrace_ops_init() on the ops in every global function. The issue is that
if two tasks call it on the same ops at the same time it is possible to
have the initialization of one corrupt the initialization of the other
call.

Create a ops_mutex to use to synchronize every initialization of the
ftrace_ops. The mutex is taken within checking the ftrace_ops flag that
states it was initializied but the flag is checked again after the mutex
has been taken. Checking first outside the mutex allows it to shortcut
having to take the mutex. But then the check needs to be done again after
the mute is taken in case of races.

Cc: stable@vger.kernel.org
Link: https://patch.msgid.link/20260902095501.6b59af20@gandalf.local.home
Fixes: f04f24fb7e48d ("ftrace, kprobes: Fix a deadlock on ftrace_regex_lock")
Reported-by: sashiko-bot@kernel.org
Close: https://lore.kernel.org/all/20260829025528.49A831F000E9@smtp.kernel.org/
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

1 files changed, 302 insertions, 0 deletions

diff --git a/lib/crypto/md5.c b/lib/crypto/md5.c
new file mode 100644
index 000000000..3d2b017a0
--- /dev/null
+++ b/lib/crypto/md5.c
@@ -0,0 +1,302 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * MD5 and HMAC-MD5 library functions
+ *
+ * md5_block() is derived from cryptoapi implementation, originally based on the
+ * public domain implementation written by Colin Plumb in 1993.
+ *
+ * Copyright (c) Cryptoapi developers.
+ * Copyright (c) 2002 James Morris <jmorris@intercode.com.au>
+ * Copyright 2025 Google LLC
+ */
+
+#include <crypto/hmac.h>
+#include <crypto/md5.h>
+#include <linux/export.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/string.h>
+#include <linux/unaligned.h>
+#include <linux/wordpart.h>
+
+static const struct md5_block_state md5_iv = {
+	.h = { MD5_H0, MD5_H1, MD5_H2, MD5_H3 },
+};
+
+#define F1(x, y, z) (z ^ (x & (y ^ z)))
+#define F2(x, y, z) F1(z, x, y)
+#define F3(x, y, z) (x ^ y ^ z)
+#define F4(x, y, z) (y ^ (x | ~z))
+
+#define MD5STEP(f, w, x, y, z, in, s) \
+	(w += f(x, y, z) + in, w = rol32(w, s) + x)
+
+static void md5_block(struct md5_block_state *state,
+		      const u8 data[MD5_BLOCK_SIZE])
+{
+	u32 in[MD5_BLOCK_WORDS];
+	u32 a, b, c, d;
+
+	memcpy(in, data, MD5_BLOCK_SIZE);
+	le32_to_cpu_array(in, ARRAY_SIZE(in));
+
+	a = state->h[0];
+	b = state->h[1];
+	c = state->h[2];
+	d = state->h[3];
+
+	MD5STEP(F1, a, b, c, d, in[0] + 0xd76aa478, 7);
+	MD5STEP(F1, d, a, b, c, in[1] + 0xe8c7b756, 12);
+	MD5STEP(F1, c, d, a, b, in[2] + 0x242070db, 17);
+	MD5STEP(F1, b, c, d, a, in[3] + 0xc1bdceee, 22);
+	MD5STEP(F1, a, b, c, d, in[4] + 0xf57c0faf, 7);
+	MD5STEP(F1, d, a, b, c, in[5] + 0x4787c62a, 12);
+	MD5STEP(F1, c, d, a, b, in[6] + 0xa8304613, 17);
+	MD5STEP(F1, b, c, d, a, in[7] + 0xfd469501, 22);
+	MD5STEP(F1, a, b, c, d, in[8] + 0x698098d8, 7);
+	MD5STEP(F1, d, a, b, c, in[9] + 0x8b44f7af, 12);
+	MD5STEP(F1, c, d, a, b, in[10] + 0xffff5bb1, 17);
+	MD5STEP(F1, b, c, d, a, in[11] + 0x895cd7be, 22);
+	MD5STEP(F1, a, b, c, d, in[12] + 0x6b901122, 7);
+	MD5STEP(F1, d, a, b, c, in[13] + 0xfd987193, 12);
+	MD5STEP(F1, c, d, a, b, in[14] + 0xa679438e, 17);
+	MD5STEP(F1, b, c, d, a, in[15] + 0x49b40821, 22);
+
+	MD5STEP(F2, a, b, c, d, in[1] + 0xf61e2562, 5);
+	MD5STEP(F2, d, a, b, c, in[6] + 0xc040b340, 9);
+	MD5STEP(F2, c, d, a, b, in[11] + 0x265e5a51, 14);
+	MD5STEP(F2, b, c, d, a, in[0] + 0xe9b6c7aa, 20);
+	MD5STEP(F2, a, b, c, d, in[5] + 0xd62f105d, 5);
+	MD5STEP(F2, d, a, b, c, in[10] + 0x02441453, 9);
+	MD5STEP(F2, c, d, a, b, in[15] + 0xd8a1e681, 14);
+	MD5STEP(F2, b, c, d, a, in[4] + 0xe7d3fbc8, 20);
+	MD5STEP(F2, a, b, c, d, in[9] + 0x21e1cde6, 5);
+	MD5STEP(F2, d, a, b, c, in[14] + 0xc33707d6, 9);
+	MD5STEP(F2, c, d, a, b, in[3] + 0xf4d50d87, 14);
+	MD5STEP(F2, b, c, d, a, in[8] + 0x455a14ed, 20);
+	MD5STEP(F2, a, b, c, d, in[13] + 0xa9e3e905, 5);
+	MD5STEP(F2, d, a, b, c, in[2] + 0xfcefa3f8, 9);
+	MD5STEP(F2, c, d, a, b, in[7] + 0x676f02d9, 14);
+	MD5STEP(F2, b, c, d, a, in[12] + 0x8d2a4c8a, 20);
+
+	MD5STEP(F3, a, b, c, d, in[5] + 0xfffa3942, 4);
+	MD5STEP(F3, d, a, b, c, in[8] + 0x8771f681, 11);
+	MD5STEP(F3, c, d, a, b, in[11] + 0x6d9d6122, 16);
+	MD5STEP(F3, b, c, d, a, in[14] + 0xfde5380c, 23);
+	MD5STEP(F3, a, b, c, d, in[1] + 0xa4beea44, 4);
+	MD5STEP(F3, d, a, b, c, in[4] + 0x4bdecfa9, 11);
+	MD5STEP(F3, c, d, a, b, in[7] + 0xf6bb4b60, 16);
+	MD5STEP(F3, b, c, d, a, in[10] + 0xbebfbc70, 23);
+	MD5STEP(F3, a, b, c, d, in[13] + 0x289b7ec6, 4);
+	MD5STEP(F3, d, a, b, c, in[0] + 0xeaa127fa, 11);
+	MD5STEP(F3, c, d, a, b, in[3] + 0xd4ef3085, 16);
+	MD5STEP(F3, b, c, d, a, in[6] + 0x04881d05, 23);
+	MD5STEP(F3, a, b, c, d, in[9] + 0xd9d4d039, 4);
+	MD5STEP(F3, d, a, b, c, in[12] + 0xe6db99e5, 11);
+	MD5STEP(F3, c, d, a, b, in[15] + 0x1fa27cf8, 16);
+	MD5STEP(F3, b, c, d, a, in[2] + 0xc4ac5665, 23);
+
+	MD5STEP(F4, a, b, c, d, in[0] + 0xf4292244, 6);
+	MD5STEP(F4, d, a, b, c, in[7] + 0x432aff97, 10);
+	MD5STEP(F4, c, d, a, b, in[14] + 0xab9423a7, 15);
+	MD5STEP(F4, b, c, d, a, in[5] + 0xfc93a039, 21);
+	MD5STEP(F4, a, b, c, d, in[12] + 0x655b59c3, 6);
+	MD5STEP(F4, d, a, b, c, in[3] + 0x8f0ccc92, 10);
+	MD5STEP(F4, c, d, a, b, in[10] + 0xffeff47d, 15);
+	MD5STEP(F4, b, c, d, a, in[1] + 0x85845dd1, 21);
+	MD5STEP(F4, a, b, c, d, in[8] + 0x6fa87e4f, 6);
+	MD5STEP(F4, d, a, b, c, in[15] + 0xfe2ce6e0, 10);
+	MD5STEP(F4, c, d, a, b, in[6] + 0xa3014314, 15);
+	MD5STEP(F4, b, c, d, a, in[13] + 0x4e0811a1, 21);
+	MD5STEP(F4, a, b, c, d, in[4] + 0xf7537e82, 6);
+	MD5STEP(F4, d, a, b, c, in[11] + 0xbd3af235, 10);
+	MD5STEP(F4, c, d, a, b, in[2] + 0x2ad7d2bb, 15);
+	MD5STEP(F4, b, c, d, a, in[9] + 0xeb86d391, 21);
+
+	state->h[0] += a;
+	state->h[1] += b;
+	state->h[2] += c;
+	state->h[3] += d;
+}
+
+static void md5_blocks(struct md5_block_state *state,
+		       const u8 *data, size_t nblocks)
+{
+	do {
+		md5_block(state, data);
+		data += MD5_BLOCK_SIZE;
+	} while (--nblocks);
+}
+
+void md5_init(struct md5_ctx *ctx)
+{
+	ctx->state = md5_iv;
+	ctx->bytecount = 0;
+}
+EXPORT_SYMBOL_GPL(md5_init);
+
+void md5_update(struct md5_ctx *ctx, const u8 *data, size_t len)
+{
+	size_t partial = ctx->bytecount % MD5_BLOCK_SIZE;
+
+	ctx->bytecount += len;
+
+	if (partial + len >= MD5_BLOCK_SIZE) {
+		size_t nblocks;
+
+		if (partial) {
+			size_t l = MD5_BLOCK_SIZE - partial;
+
+			memcpy(&ctx->buf[partial], data, l);
+			data += l;
+			len -= l;
+
+			md5_blocks(&ctx->state, ctx->buf, 1);
+		}
+
+		nblocks = len / MD5_BLOCK_SIZE;
+		len %= MD5_BLOCK_SIZE;
+
+		if (nblocks) {
+			md5_blocks(&ctx->state, data, nblocks);
+			data += nblocks * MD5_BLOCK_SIZE;
+		}
+		partial = 0;
+	}
+	if (len)
+		memcpy(&ctx->buf[partial], data, len);
+}
+EXPORT_SYMBOL_GPL(md5_update);
+
+static void __md5_final(struct md5_ctx *ctx, u8 out[MD5_DIGEST_SIZE])
+{
+	u64 bitcount = ctx->bytecount << 3;
+	size_t partial = ctx->bytecount % MD5_BLOCK_SIZE;
+
+	ctx->buf[partial++] = 0x80;
+	if (partial > MD5_BLOCK_SIZE - 8) {
+		memset(&ctx->buf[partial], 0, MD5_BLOCK_SIZE - partial);
+		md5_blocks(&ctx->state, ctx->buf, 1);
+		partial = 0;
+	}
+	memset(&ctx->buf[partial], 0, MD5_BLOCK_SIZE - 8 - partial);
+	*(__le64 *)&ctx->buf[MD5_BLOCK_SIZE - 8] = cpu_to_le64(bitcount);
+	md5_blocks(&ctx->state, ctx->buf, 1);
+
+	cpu_to_le32_array(ctx->state.h, ARRAY_SIZE(ctx->state.h));
+	memcpy(out, ctx->state.h, MD5_DIGEST_SIZE);
+}
+
+void md5_final(struct md5_ctx *ctx, u8 out[MD5_DIGEST_SIZE])
+{
+	__md5_final(ctx, out);
+	memzero_explicit(ctx, sizeof(*ctx));
+}
+EXPORT_SYMBOL_GPL(md5_final);
+
+void md5(const u8 *data, size_t len, u8 out[MD5_DIGEST_SIZE])
+{
+	struct md5_ctx ctx;
+
+	md5_init(&ctx);
+	md5_update(&ctx, data, len);
+	md5_final(&ctx, out);
+}
+EXPORT_SYMBOL_GPL(md5);
+
+static void __hmac_md5_preparekey(struct md5_block_state *istate,
+				  struct md5_block_state *ostate,
+				  const u8 *raw_key, size_t raw_key_len)
+{
+	union {
+		u8 b[MD5_BLOCK_SIZE];
+		unsigned long w[MD5_BLOCK_SIZE / sizeof(unsigned long)];
+	} derived_key = { 0 };
+
+	if (unlikely(raw_key_len > MD5_BLOCK_SIZE))
+		md5(raw_key, raw_key_len, derived_key.b);
+	else
+		memcpy(derived_key.b, raw_key, raw_key_len);
+
+	for (size_t i = 0; i < ARRAY_SIZE(derived_key.w); i++)
+		derived_key.w[i] ^= REPEAT_BYTE(HMAC_IPAD_VALUE);
+	*istate = md5_iv;
+	md5_blocks(istate, derived_key.b, 1);
+
+	for (size_t i = 0; i < ARRAY_SIZE(derived_key.w); i++)
+		derived_key.w[i] ^= REPEAT_BYTE(HMAC_OPAD_VALUE ^
+						HMAC_IPAD_VALUE);
+	*ostate = md5_iv;
+	md5_blocks(ostate, derived_key.b, 1);
+
+	memzero_explicit(&derived_key, sizeof(derived_key));
+}
+
+void hmac_md5_preparekey(struct hmac_md5_key *key,
+			 const u8 *raw_key, size_t raw_key_len)
+{
+	__hmac_md5_preparekey(&key->istate, &key->ostate, raw_key, raw_key_len);
+}
+EXPORT_SYMBOL_GPL(hmac_md5_preparekey);
+
+void hmac_md5_init(struct hmac_md5_ctx *ctx, const struct hmac_md5_key *key)
+{
+	ctx->hash_ctx.state = key->istate;
+	ctx->hash_ctx.bytecount = MD5_BLOCK_SIZE;
+	ctx->ostate = key->ostate;
+}
+EXPORT_SYMBOL_GPL(hmac_md5_init);
+
+void hmac_md5_init_usingrawkey(struct hmac_md5_ctx *ctx,
+			       const u8 *raw_key, size_t raw_key_len)
+{
+	__hmac_md5_preparekey(&ctx->hash_ctx.state, &ctx->ostate,
+			      raw_key, raw_key_len);
+	ctx->hash_ctx.bytecount = MD5_BLOCK_SIZE;
+}
+EXPORT_SYMBOL_GPL(hmac_md5_init_usingrawkey);
+
+void hmac_md5_final(struct hmac_md5_ctx *ctx, u8 out[MD5_DIGEST_SIZE])
+{
+	/* Generate the padded input for the outer hash in ctx->hash_ctx.buf. */
+	__md5_final(&ctx->hash_ctx, ctx->hash_ctx.buf);
+	memset(&ctx->hash_ctx.buf[MD5_DIGEST_SIZE], 0,
+	       MD5_BLOCK_SIZE - MD5_DIGEST_SIZE);
+	ctx->hash_ctx.buf[MD5_DIGEST_SIZE] = 0x80;
+	*(__le64 *)&ctx->hash_ctx.buf[MD5_BLOCK_SIZE - 8] =
+		cpu_to_le64(8 * (MD5_BLOCK_SIZE + MD5_DIGEST_SIZE));
+
+	/* Compute the outer hash, which gives the HMAC value. */
+	md5_blocks(&ctx->ostate, ctx->hash_ctx.buf, 1);
+	cpu_to_le32_array(ctx->ostate.h, ARRAY_SIZE(ctx->ostate.h));
+	memcpy(out, ctx->ostate.h, MD5_DIGEST_SIZE);
+
+	memzero_explicit(ctx, sizeof(*ctx));
+}
+EXPORT_SYMBOL_GPL(hmac_md5_final);
+
+void hmac_md5(const struct hmac_md5_key *key,
+	      const u8 *data, size_t data_len, u8 out[MD5_DIGEST_SIZE])
+{
+	struct hmac_md5_ctx ctx;
+
+	hmac_md5_init(&ctx, key);
+	hmac_md5_update(&ctx, data, data_len);
+	hmac_md5_final(&ctx, out);
+}
+EXPORT_SYMBOL_GPL(hmac_md5);
+
+void hmac_md5_usingrawkey(const u8 *raw_key, size_t raw_key_len,
+			  const u8 *data, size_t data_len,
+			  u8 out[MD5_DIGEST_SIZE])
+{
+	struct hmac_md5_ctx ctx;
+
+	hmac_md5_init_usingrawkey(&ctx, raw_key, raw_key_len);
+	hmac_md5_update(&ctx, data, data_len);
+	hmac_md5_final(&ctx, out);
+}
+EXPORT_SYMBOL_GPL(hmac_md5_usingrawkey);
+
+MODULE_DESCRIPTION("MD5 and HMAC-MD5 library functions");
+MODULE_LICENSE("GPL");